Use a "slock" variable as done in multiple places to simplify the code.
The locking stay the same. This is just a first step to simplify this
mess.
Also get rid of the return value of the function, it is never checked.
ok?
Index: uvm/uvm_pdaemon.c
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_pdaemon.c,v
retrieving revision 1.101
diff -u -p -r1.101 uvm_pdaemon.c
--- uvm/uvm_pdaemon.c 28 Jun 2022 19:31:30 -0000 1.101
+++ uvm/uvm_pdaemon.c 18 Aug 2022 10:44:52 -0000
@@ -102,7 +102,7 @@ extern void drmbackoff(long);
*/
void uvmpd_scan(struct uvm_pmalloc *);
-boolean_t uvmpd_scan_inactive(struct uvm_pmalloc *, struct pglist *);
+void uvmpd_scan_inactive(struct uvm_pmalloc *, struct pglist *);
void uvmpd_tune(void);
void uvmpd_drop(struct pglist *);
@@ -377,17 +377,16 @@ uvm_aiodone_daemon(void *arg)
* => we handle the building of swap-backed clusters
* => we return TRUE if we are exiting because we met our target
*/
-
-boolean_t
+void
uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst)
{
- boolean_t retval = FALSE; /* assume we haven't hit target */
int free, result;
struct vm_page *p, *nextpg;
struct uvm_object *uobj;
struct vm_page *pps[SWCLUSTPAGES], **ppsp;
int npages;
struct vm_page *swpps[SWCLUSTPAGES]; /* XXX: see below */
+ struct rwlock *slock;
int swnpages, swcpages; /* XXX: see below */
int swslot;
struct vm_anon *anon;
@@ -402,7 +401,6 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
*/
swslot = 0;
swnpages = swcpages = 0;
- free = 0;
dirtyreacts = 0;
p = NULL;
@@ -431,18 +429,14 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
*/
uobj = NULL;
anon = NULL;
-
if (p) {
/*
- * update our copy of "free" and see if we've met
- * our target
+ * see if we've met our target
*/
free = uvmexp.free - BUFPAGES_DEFICIT;
if (((pma == NULL || (pma->pm_flags & UVM_PMA_FREED)) &&
(free + uvmexp.paging >= uvmexp.freetarg << 2)) ||
dirtyreacts == UVMPD_NUMDIRTYREACTS) {
- retval = TRUE;
-
if (swslot == 0) {
/* exit now if no swap-i/o pending */
break;
@@ -450,9 +444,9 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
/* set p to null to signal final swap i/o */
p = NULL;
+ nextpg = NULL;
}
}
-
if (p) { /* if (we have a new page to consider) */
/*
* we are below target and have a new page to consider.
@@ -460,11 +454,12 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
uvmexp.pdscans++;
nextpg = TAILQ_NEXT(p, pageq);
+ anon = p->uanon;
+ uobj = p->uobject;
if (p->pg_flags & PQ_ANON) {
- anon = p->uanon;
KASSERT(anon != NULL);
- if (rw_enter(anon->an_lock,
- RW_WRITE|RW_NOSLEEP)) {
+ slock = anon->an_lock;
+ if (rw_enter(slock, RW_WRITE|RW_NOSLEEP)) {
/* lock failed, skip this page */
continue;
}
@@ -474,23 +469,20 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
*/
if (pmap_is_referenced(p)) {
uvm_pageactivate(p);
- rw_exit(anon->an_lock);
+ rw_exit(slock);
uvmexp.pdreact++;
continue;
}
if (p->pg_flags & PG_BUSY) {
- rw_exit(anon->an_lock);
+ rw_exit(slock);
uvmexp.pdbusy++;
- /* someone else owns page, skip it */
continue;
}
uvmexp.pdanscan++;
} else {
- uobj = p->uobject;
KASSERT(uobj != NULL);
- if (rw_enter(uobj->vmobjlock,
- RW_WRITE|RW_NOSLEEP)) {
- /* lock failed, skip this page */
+ slock = uobj->vmobjlock;
+ if (rw_enter(slock, RW_WRITE|RW_NOSLEEP)) {
continue;
}
/*
@@ -499,14 +491,13 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
*/
if (pmap_is_referenced(p)) {
uvm_pageactivate(p);
- rw_exit(uobj->vmobjlock);
+ rw_exit(slock);
uvmexp.pdreact++;
continue;
}
if (p->pg_flags & PG_BUSY) {
- rw_exit(uobj->vmobjlock);
+ rw_exit(slock);
uvmexp.pdbusy++;
- /* someone else owns page, skip it */
continue;
}
uvmexp.pdobscan++;
@@ -539,10 +530,8 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
/* remove from object */
anon->an_page = NULL;
- rw_exit(anon->an_lock);
- } else {
- rw_exit(uobj->vmobjlock);
}
+ rw_exit(slock);
continue;
}
@@ -552,11 +541,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
*/
if ((pma == NULL || (pma->pm_flags & UVM_PMA_FREED)) &&
(free + uvmexp.paging > uvmexp.freetarg << 2)) {
- if (anon) {
- rw_exit(anon->an_lock);
- } else {
- rw_exit(uobj->vmobjlock);
- }
+ rw_exit(slock);
continue;
}
@@ -569,11 +554,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
if ((p->pg_flags & PQ_SWAPBACKED) && uvm_swapisfull()) {
dirtyreacts++;
uvm_pageactivate(p);
- if (anon) {
- rw_exit(anon->an_lock);
- } else {
- rw_exit(uobj->vmobjlock);
- }
+ rw_exit(slock);
continue;
}
@@ -640,11 +621,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
&p->pg_flags,
PG_BUSY);
UVM_PAGE_OWN(p, NULL);
- if (anon)
- rw_exit(anon->an_lock);
- else
- rw_exit(
- uobj->vmobjlock);
+ rw_exit(slock);
continue;
}
swcpages = 0; /* cluster is empty */
@@ -676,10 +653,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
*/
if (swap_backed) {
if (p) { /* if we just added a page to cluster */
- if (anon)
- rw_exit(anon->an_lock);
- else
- rw_exit(uobj->vmobjlock);
+ rw_exit(slock);
/* cluster not full yet? */
if (swcpages < swnpages)
@@ -791,10 +765,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
/* !swap_backed case: already locked... */
if (swap_backed) {
- if (anon)
- rw_enter(anon->an_lock, RW_WRITE);
- else
- rw_enter(uobj->vmobjlock, RW_WRITE);
+ rw_enter(slock, RW_WRITE);
}
#ifdef DIAGNOSTIC
@@ -855,10 +826,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
* the inactive queue can't be re-queued [note: not
* true for active queue]).
*/
- if (anon)
- rw_exit(anon->an_lock);
- else if (uobj)
- rw_exit(uobj->vmobjlock);
+ rw_exit(slock);
if (nextpg && (nextpg->pg_flags & PQ_INACTIVE) == 0) {
nextpg = TAILQ_FIRST(pglst); /* reload! */
@@ -877,7 +845,6 @@ uvmpd_scan_inactive(struct uvm_pmalloc *
uvm_lock_pageq();
}
}
- return (retval);
}
/*
@@ -925,10 +892,6 @@ uvmpd_scan(struct uvm_pmalloc *pma)
* to inactive ones.
*/
- /*
- * alternate starting queue between swap and object based on the
- * low bit of uvmexp.pdrevs (which we bump by one each call).
- */
pages_freed = uvmexp.pdfreed;
(void) uvmpd_scan_inactive(pma, &uvm.page_inactive);
pages_freed = uvmexp.pdfreed - pages_freed;
